Apparatus for tunnelling



Sept. 3, 1957 E. K. BRIDGE APPARATUS FOR TUNNELLING Filed Nov. 22, 1954.

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. .WAWHHMH@- .ED-l EA Y I Inventor ER-/c KENNE-HR/e By. .5, z. E

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Sept. 3, 1957 E. K. BRIDGE 2,804,754

APPARATUS FOR TUNNELLING Filed Nov. 22, '1954 3 Sheets-Sheet 2 l Inventor ERIC KENNETH HWG-.E

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y. Prana- 1' A ttorne y Sept. 3, 1957 E. K. BRIDGE APPARATUS FOR TUNNELLING 3 Sheets-Sheet 5 Filed Nov. 22, 1954 Efe/c KENNETH. 23R/BGE United States Patent F"ffice APPARATUS FOR TUNNELLING Eric Kenneth Bridge, Epsom, England Application November 22, 1954, Serial No. 470,421

Claims. (Cl. 61-84) This invention is for improvements in or relating to a method of and apparatus for tunnelling through earth as distinct from rock.

Various tunnelling shields are already known and in use and these tunnelling shields involve the use of hydraulic jacks, electric motors or other motive power means for driving the shields forward and also for rotating the earth-cutting tools.

The present invention has for an object to provide a method of tunnelling and a tunnelling shield which will obviate the necessity for separate power drives for the shield and for the cutter blades and may effect consider- .able economies by eliminating the step of grouting between the tunnel-lining and the ground and by 4permitting the erection of the lining to take place during the forward movement of the shield and, therefore, in accordance with the present invention there is provided a method of vtunnelling which comprises rotating a shield frame, carrying fixed cutter-blades, by means of a tangentially-disposed jacking mechanism acting on the radial side face of the .end block of spirally-disposed lining blocks or on a reaction member or members abutting against the face of said end block, the shield-frame being forced forwardly by the engagement of thrust-rollers or thrust-plates mounted thereon with the forward facing surfaces .of the tunnel-lining blocks.

Where the line of a tunnel being driven requires to be otherwise than on a straight line or where, for any reason whatsoever, the direction of movement of the shield has to be controlled to compensate for any deviation from the desired line, the invention includes a method wherein the direction of movement of the shield frame is controlled by adjustment of a forwardly projecting pointed or ring member engaging with the earth in advance of the cutter blades.

Instead of, or in addition to, the above-mentioned method of controlling the direction of movement of the shield-frame, such control could be effected by the use of precast blocks of varying predetermined thickness in the direction of the axis of the tunnel so that by appropriately varying the thickness of each layer of tunnel-lining blocks or by the insertion of packings in the circumferential joints between adjacent layers of blocks, the direction of movement of the shield-frame could be controlled. Further, or alternatively, such control may be effected by providing jacks arranged around the circumference of the shield to act parallel with the axis thereof and operating ent invention is quite clearly distinguished from this prior proposal in that in the present invention the shield is amarsi yPatented Sept. 3, 1957 Z moved forwardly by engagement of thrust members, e.' g. rollers or slides, with the forwardly facing surfaces of the tunnel-lining blocks as distinct from being moved forward by engagement with rails or like tracks formed on the interior cylindrical surface of the tunnel-lining blocks.

The apparatus provided by the present invention Vfor tunnelling comprises a rigid cylindrical shield-frame, a'

plurality of cutter blades mounted on said frame to e11- gagev with and cut earth in front of the leading edge of the shield-frame, one or more jacking mechanisms disposed at or adjacent the trailing edge of the shieldframe and mounted substantially tangentially thereon and a plurality of thrust members, e. g. rollers, balls or slides, each so disposed in a spiral at or adjacent the trailing edge of the shield-frame as to bear, preferably through an intermediate thrust plate, against the forward facing surface of spirally placed tunnel-lining blocks. In addition to the thrust members, support members may also be mounted upon the shield-frame to engage with the circumferential internal surface of the tunnel-lining blocks to hold them rmly in position until the next succeeding tunnel-lining blocks have been placed in position as the shield-frame advances through the earth. Y i

VWhere more than one jacking 'mechanism is provided for effecting rotation of the shield-frame, these jacking mechanisms may be arranged to operate in synchronisrn or, alternatively, they may be arrangedto operate successively, in which latter case it may be possible to arrange for a substantially uniform rotation of the shield-frame providing for continuous cutting of the tunnel.

` Where a single jacking mechanism is employed or where a plurality of such jacking mechanisms are operating in synchronism, it is a feature of the invention that an auxiliary holding jack is mounted on the shield-frame alongside the one or each of the saidjacking mechanisms for operation whenY said jacking mechanisms are, or are being, retracted; whereA an intermediate thrust plate is provided the return action of the auxiliary or main jacks may be arranged to pull'the plate round between the concrete blocks and the thrust members, after the last blocks of the spiral have been held by the holding jacks but before the rotation of the shield commences for the next block.. Y

In order to clear from the surface of the tunnel being cut, the earth, clay or other muck, it is a feature of the invention that la centre hopper and associated conveyor belt mechanism are suspended from'a bar or tube mounted axially in the shield-frame. In this construction it is preferred that the interior of theshield-frame isformed with compartments opening radially inwardly to receive material dislodged by the cutter blades and to discharge it into said hopper. Y

In order to control the direction of movement of the shield-frame, it is a feature of `the invention that there is provided a pointed or ring member mounted axially of said shield-frame to project beyondthe cutter blades at its forward end and adjustably mounted at or towards its rear end to enable the direction of the axis of the pointed member to be varied; the pointed or ring member may conveniently be housed in the axial tube from which the centre hopper and conveyor belt above-mentioned are suspended. A feature of the construction` forradjustment of the pointed or ring member consists in that Ya double eccentric arrangement is employed for the adjustable mounting of said pointed member, each of the eccentrics being separately adjustable whereby the axis of the member can be directed in any desired direction.

The apparatus of the invention also includes an arrangement in which an automatically -operated liningblock placing mechanism is mounted on a subsidiary framework secured to Ysaid shield-frame or otherwise, whilst a further convenient arrangement which is possible in the apparatus of the present invention is that a hydraulic junction box may be mounted on the axial bar or tube on which the hopper and conveyor belt are suspended so that a single hydraulic or pneumatic pressure line may be led to the junction box, which does not rotate as the shield rotates, the necessary power lines being takenofrom the junction box to the various hydraulic or `pneumatically-operated parts of the shield-frame.

The following is a description of two embodiments of shield-frame in accordance with the present invention rwith reference to the accompanying drawings, in which- Figure 1 is a cross-sectional elevation of one form of Yrotating tunnelling shield;

Figure 2 is two sections respectively Valong .the line IIA-,IIA of Figure'l designated A, and'the lower half a section along the line 'IIB-IIB ldesignated B;

Figure 3 is an enlarged view of the means for guiding the tunnelling shield;

Figure tV is a cross-section and Y FigureS is a cross-section along the line V-V of Figure 4.

Throughout the drawings `like reference numerals denote like parts. Y

A cylindrical shell 1 of steel is provided which has welded to the vforward edge thereof a stiifening rim 2 provided with a circular forwardly-facing cutting edge 3, the rearward edge 4 of the shell ,1 being formed spirally with either-one or more starts depending upon the number of jacks to be employed. In the embodiment being described, the rear or trailing edge 4 of the shell 1 .is formed with a two-start spiral and vtwo hydraulic jacks 5 are mounted tangentially on the rear edge 4 of the shell each adjacent one of the starts of the spiral thereof. Adjacent the main jacks 5 there are provided, as seen in .Figure 5, auxiliary jacks 32 for holding the shield-frame 1 as a Whole in position when the main jacks 5 are being retracted.

At the leading edge of the shell, there are disposed the cutter blades 6 which are detachably mounted on a framework 7 welded or otherwise secured to the steel shell 1. o

Rearwardly of the cutter blades 6 aonumber of compartments 8 are formed by welding or otherwise securing thereto steel plates 9 in such a way as to form compartments around theinner periphery of the Yshield-frame 1 to receive the clay or other muck cut by cutter blades 6 during rotation ofthe shield-frame. Mounted in the centre of the framework 7 supporting the cutter blades 6 is a steel tube 10 disposed along the central axis of the shield-,frame 1. Mounted upon the rearward end of this steel tube 10 is a hopperll so placed as to` receive muck discharged from the` compartments above referred to during rotation of the shield-frame 1 whilst, in addition, a conveyor `belt end-runner 12 is also mounted so as to be suspended from the steel tube 10 whereby both the hopper 11 and the conveyor 13 remain suspended without rotating during rotation of the shield-frame. Located within the steel tube 10 is an arrangement, best seen in Figure 3, for controlling the direction of movement of the shield-frame 1 during tunnelling which comprises a rod or tube 14 disposed centrally within the above-mentioned steel tube 10 and carrying at its forward end a uted point 1S having a number of blades 16. At the root of the fluted point 15 is a spherical bearing surface 17 which is housed within a cup-bearing 18 secured in the forward end of the above-mentioned steel tube 10.

Y Mounted in the rearward end of the steel tube 10 lare two 'eccentrics 19 and 20, one, 19, being mounted Within the tube itself and the second, 2t), in which the rear end of the tube 14 carrying the fluted point 15 is mounted, being mounted within the eccentric bore of the rstmentioned eccentric 19. It will be appreciated that, by rotating the two eccentrics, any desired degree of eccenof a second embodiment,

tricity can be arranged within the limit of relative adjustment of the two eccentrics with respect to one an` other; the two eccentrics 19 and 20 may be provided with hand-operated wheels 21, 22 upon which there may be formed marks or projections indicating when the eccentrics are fully opposed to one another and thus compensate one another to leave the uted point 15 directed along the central longitudinal axis of the shield-frame. Mounted around the outside of the steel tube 10 is a junction box 23 into which is connected the main hydraulic pressure supply main 24 and from which are taken the hydraulic pressure connections 25 to the jacks 5. Mounted on the central frame 7 is a supporting ring 26 on which the hopper 11, for receiving the muck discharged from the cutter blades 6, runs on rollers 27 so that as the frame rotates, the muck hopper 11 can remain suspended in a iixed and normal situation; also suspended in this manner is the arm carrying the end runner 12 for the conveyor belt 13 for carrying away the muck discharged into the hopper '11 from the compartments 8 as the shield rotates.

Mounted on the trailing edge 4 of the steel shell 1 are a number of thrust rollers 28 which are spring-loaded as at 29 so as to bear through an intermediate thrust plate 30 on the forwardly-facing surfaces of the lining blocks 31 of the tunnel. These thrust rollers 28 operate, as the shield-frame 1 is rotated by the jacks 5, toY push thev shield-frame forwardly by running round on the spiral track formed by the thrust plate 30 resting against for- -Wardly facing edges of the tunnel-lining blocks last-laid,

the plate being pulled round by thereturn action of the auxiliary jacks 32,

Mounted on the trailing edge 4 of the steel shell 1 'and facing rearwardly are supplementary jacks 33 for controlling the alignment of the shell 1 uduring operation. The alignmentjacks 33 are mounted with their longitudinal axis parallel to the tunnel axis and are so arranged as to engage with the thrust plate 30 through lthe thrust rollers 2S or they may bear directly on the 'thrust plates 30. The alignment jacks 33 are independently operable so as to enable the direction of the shield 1 to be controlled and, as the shield rotates, so will the vindividual alignment jacks 33 be brought into operation one by one so as to maintain pressure on the shield 1 'at the'same part of the tunnel being excavated.

During the rotation of the shield-frame 1, therefore, under the influence of the main hydraulic jacks 5, the shield-frame rotates carrying with it the cutter blades 6 and being at the same timemoved forward so that the tunnel is excavated. When the main jacks 5 have been 'fully'extended, the auxiliary holding jacks 32 operate 'to maintain the last-laid lining block 31 in position and the main jack 5 is then retracted and a fresh liningblock 31 is placed in position read for the next operation of the main jack 5 engaging with the radial side face of the end block. ,In order to ensure that the blocks are retained in position, the present embodiment of shieldframe 1 alsoV has provided thereon support rollers 34 running on the internal circumferential surface of the lining-blocks to hold them in position after they have been laid and before they have become firmly settled into position and retained in place by the next layer of blocks. f

This embodiment of shield-frame being described also has hydraulically or electricallyroperated block-placers 35 which are carried on a frame 36 running on rails 37 secured to the rearwardly-facing sides of the compartments 8 previously described for receiving muck cut by the cutter blades 6. The block-placer 35 comprises a pivotally mounted arm 38 which is moved substantially radially by means of a hydraulic piston and cylinder arrangement 39 and which carries at its end means 40 for holding a lining block and placing it into the desired position when the main jack is retracted.

f Referring now to the embodiment illustrated in Figures 4 and 5, the construction here is broadly similar to that of the first embodiment described and differs therefrom in that in place of the flat face of the shield formed by the cutter blades 6, the present embodiment has a 4hemispherical front using curved cutter blades or clay knives.

Referring to Figure 4 of the drawings, the shield 1 is ,generally similar to the shield of the embodiment illustrated in Figure 1 but at its rearward or trailing edge the shield is enlarged to a slightly greater diameter as shown at 41 and its trailing edge is channelled as at 42 to accommodate a number of steel balls 43 which are distributed around the channel 42 and bear against a thrustplate 44 which is adapted to abut against the forwardly facing surfaces of the lining blocks 31. The thrust-plate acts as a reaction member to thrust the shield forward into the earth.

At the forward edge of the shield 1 there is attached a hemispherical cutter assembly comprising a plurality of curved clay knives 45 which are attached to a frame member 46 secured to the front edge of the shield 1, the clay knives 45 being provided with stiifening rings 47 midway along their length, each clay knife being secured at its forward end to a ring in which the steering tube is carried.

In View of the fact that the forwardly disposed hemispherical cutting surface formed by the clay knives 45 ploughs out a hole which is of lesser diameter than the rearward part of the shield 1, it is necessary to provide ploughs 48 which excavate the additional thickness of earth necessary to bring the size of the tunnel in which the blocks are being laid to the appropriate overall diameter. Preferably two of these ploughs 48 are provided disposed diagonally opposite to one another. The ploughs are so arranged as to divert the muck forwardly into the forward part of the shield so that the muck collecting from the ploughs 48 as well as that collecting from the clay knives 45 can be, if desired, transferred to a hopper and conveyor such as described in respect of Figure 1 or, alternatively, can be cleared from Within the shield-frame by any other suitable means.

Disposed rearwardly of the hemispherical assembly of clay knives is a cover-plate or plates 49 which are adapted to prevent the muck from interfering with the various jacks, appropriate orifices Si) being formed in the coverplate to enable the placing of fresh tunnel-lining blocks 31 when the main jacks are retracted at each operation thereof.

As will be seen from the sectional view shown in Figure 5, the thrust-plate 30 is disposed to lie against the top surface of the blocks 31 and is connected to an auxiliary jack 32 which is operated so as to move the thrust-plate 30 around stepwise as each new block is inserted in position and the main jack 5 is retracted.

At the end of the thrust-plate 3) nearest the end of the placed blocks 31 there is formed a pawl 51 which is adapted to engage in the holes formed in the face of the blocks 31 by which they are placed in position by the block-placing device described in connection with Figure l, the holes being those with which the holding means 40 of the block placer 35 engage. It will be appreciated that with the auxiliary jack operated so as to exert a holding effort when the pawl 51 is in engagement with the hole in the block 31, the last several liningblocks which have been placed in position are not only held firmly in a radial direction against the wall of the newly excavated tunnel, but also the end block-member is pushed in a circumferential direction against the other blocks in the spiral. When the new block has been placed in position after retraction of the main jack 5, the auxiliary jack 32 is retracted after the main jack has been re-engaged so as to move the plate 30 to the position in which the pawl 51 can engage in the hole in the last-laid block to hold it in position whereafter the main jack 5 is actuated to rotate the shield.

The other details of construction illustrated in the two figures are the same or closely similar to the details illustrated in Figures 1, 2 and 3 and, as previously indicated, like reference numerals indicate like parts.

It will be appreciated that with this embodiment the tunnel is first opened out to one size by the clay knives" and then just prior to the point at which fresh tunnellining blocks are placed, the tunnel is opened up further by the two ploughs mounted at the rear of the shield so that the excavation of the tunnel takes place in two stages, the latter of which, however, may consist only in a re` moval of a matter of a few inches of earth to form the inal surface of the tunnel against which the tunnel-lining blocks are to be laid.

It will be appreciated from the foregoing description of two embodiments of shield-frame in accordance with the invention that there is provided an apparatus and method in which tunnel-lining blocks,` conveniently made of precast concrete and in the desired and necessary shape, are laid in the form of a spiral as the shield is driven forwardly into the earth and Icuts the tunnel,` the cutting or excavation of the tunnel being effected by the rota-` tion of the shield-frame as a whole by means of a jack or jacks, the shield being pushed forwardly into the earth by thrust members which react through a thrustplate against the forward face of the last-placed row of spiral lining blocks.

Thus, the whole power for excavating the earth and for thrusting the shield-frame into the excavated space is derived from the tangentially-disposed main jacks operating on the end-faces of the spiral of lining blocks, thereby providing a very greatly simplified shield-frame and method of tunnelling as compared with prior constructions a`nd methods.

The present invention has the advantage that the liningblocks can be of standard size and shalpe including the standard sizes and shapes of blocks for use where the tunnel is to be curved, whilst there may also be provided -Y blocks of lesser circumferential length than the normal in order to ensure a breaking of the joints between the blocks in successive layers.

By the present invention the lining-blocks are firmly held in position ybecause of the thrust of the mainjacks during the rotating of the shield-frame, the blocks therefore being pressed tightly against one another and also against the excavated tunnel surface. The faces of the blocks, which are to abut against other blocks, are preferably coated with bitumen or other sealing composition, so that the tunnel-lining is a substantially finished lining immediately in the rear of the shield-frame as it progresses through the earth. In many instances it may prove to be unnecessary to do any bonding of the blocks to one another after they have been placed in position, except possibly when the shield-frame is stopped or when it is necessary to break out from the lining of the tunnel.

It is to be appreciated that the invention is not limited by the description of the foregoing embodiments of the invention above described but is concerned broadly with the method and apparatus hereinbefore envisaged and described generally.

I claim:

l. Apparatus for tunnelling comprising a rigid cylindrical shield-frame, a plurality of cutter blades mounted fast on said frame to engage with and cut earth in front of the leading edge of the shield-frame, a jacking mechanism disposed adjacent the trailing edge of the shieldframe and mounted substantially tangentially thereon so disposed as to act on the radial side face of the end block of spirally disposed tunnel-lining blocks and a plurality of thrust members each so disposed in a spiral adjacent the trailing edge of the shield-frame as to bear against the forward facing surfaces of said spirally-placed tunnellining blocks.

2. Apparatus according to claim l wherein a support member is disposed on said shield-frame in such a manner as to support the last-laid lining block in position.

3. Apparatus according to yclaim `2 wherein said support member comprises rollers.

4. Apparatus according to yclaim 2 wherein said support member comprises a continuous supporting surface adapted to engage with a plurality of lining blocks.

5. Apparatus according, to claim 4 wherein an auxiliary holding jack is mounted on said shield-frame and said continuous supporting surface is provided `with a datent member and is connected to said auxiliary holding jack whereby the detent member being in engagement with the last-laid lining block, the shield-frame and the lining blocks may be retained in position when the main jacking mechanism is inot operating. Y

6. Apparatus according to claim l wherein a centre hopper and associated conveyor belt `mechanism are suspended from a mounting disposed axially in the shieldframe.

7. Apparatus according to claim 1 wherein a guide member is mounted axially of said shield-frame to project beyond the cutter blades at its forward end and is 8 adjustably mounted ladjacent its rear `end to enable the direction of the axis of the said member to be varied.

8. Apparatus according to claim 1 wherein a liningblock placing mechanism is mounted on a subsidiary frameworksecured `to said shield-frame.

9. Apparatus according to claim l wherein a plough is mounted adjacent the trailing edge of said shield-frame to excavate ,the tunnel to a 'greater diameter than that excavated bysaid cutter blades.

10. Apparatus according to claim 1 wherein the cutter blades are clay knives shaped to form a hemispherical cutting surface.

References Cited in the le of this patent UNITED STATES PATENTS 739,969 Young Sept. 29,V 1903 1,336,7894 Sheen Apr. 13, 1920 1,351,137 Sheen Aug. 31, 1920 FOREIGN PATENTS 1,424 Great Britain 1876 278,219 Switzerland Jan. 3, 1952 

